Abstract: Objective To research the three-dimensional reconstruction of tooth crown and root with digital models and setup in oral clinical application. Methods Obtaining cone-beam computed tomography（CBCT）teeth models and structured light-scanned crown models of 15 patients，selected iterative closest point calculation to register two kind digital models totally. After registration completely，CBCT roots model and structured light-scanned crowns were integrated a new one. Then led each integrated tooth in Teeth Arrangement software to array according ideal occlusion criterion，and tested rationality of roots arrangement online after importing jaws. Ultimately，evaluated teeth arrangement results by peer assessment rating（PAR）index. Results CBCT and structured light-scanned model registration errors of maxilla was（0.135 ± 0.015）mm，and mandible was（0.130 ± 0.022）mm. In 15 patients，the setup of tooth was introduced into the jaw，all of which had different degrees of root protrusion. Evaluating PAR index points about digital and stone models before and after setup，the ICC showed that two kind models were highly correlated in all measurements and all the ICC were greater than 0.800.Weighted PAR scores of all patients after setup has decreased more than 90% to before setup and this kind of setup result tested better. Weighted PAR score of two thirds of patients after setup has decreased more than 22 points and the setup result tested much better. Conclusion It is feasible and necessary to apply the three-dimensional digital model of dental crown and root integration to oral clinic.

Key words: cone-beam computed tomography, CBCT；structured light-scanned；digital setup；three-dimensional tooth crown and root model

摘要： 目的 建立牙齿三维冠根整合数字化模型并进行虚拟排牙，探讨其在口腔临床中的应用。方法 获取15例患者锥形束CT（CBCT）的全牙列模型和结构光的牙冠模型，行迭代最近点算法对两种模型进行全局配准，在最佳匹配后截取CBCT牙根和基于结构光扫描的牙冠整合成新的牙齿模型。利用自行研发软件Teeth Arrangement对整合后的牙齿模型按照理想牙合标准进行排列并导入颌骨进行在线验证。最后采用同行评估等级（peer assessment rating，PAR）指数评价排牙效果。结果 15例患者的结构光扫描模型与CBCT配准偏差数据符合正态分布，上颌配准偏差为（0.135 ± 0.015）mm，下颌配准偏差为（0.130 ± 0.022）mm。15例患者的排牙模型导入颌骨中，全部出现了不同程度的牙根突出颌骨。采用PAR指数对排牙前数字化模型与石膏模型错牙合程度分析，两者具有高度一致性（ICC > 0.800）。全部患者排牙前后模型PAR加权值减少90 % 以上，排牙前后效果比较为改善；2/3患者PAR加权值减少22分以上，排牙前后效果比较为极大改善。结论 将牙齿三维冠根整合数字化模型应用到口腔临床具有可行性及必要性。

关键词: 锥形束CT, 结构光扫描, 数字化排牙, 三维冠根模型